Yesterday, I was idly contemplating the popular notion that we might be living in a simulation. (I never get tired of thinking about this.) As I considered the purpose(s) such a simulation might serve, a memory floated up of someone—I forget who (maybe Sam Harris)—saying that the possibility of being in a simulation should motivate us to live as interesting a life as possible in order to give the simulator overlords a good reason to keep the program running.

This led to a whole cascade of thoughts.

Now, before I say anything else, let me acknowledge that Harris’s comment was clearly tongue-in-cheek. Correspondingly, the following analysis is also tongue-in-cheek; but that doesn’t make it any less interesting. So here we go.

I’ve run quite a few simulations for my physics research, so I know a little about them. Here are some key points:

  1. Usually, no one is watching a simulation while it’s running (except to check that it is still running).
  2. Furthermore, the details of everything that happens during the course of a simulation are mostly lost; only key data values are recorded for analysis.
  3. Simulations are usually run many, many times (i.e., thousands or even millions of times), with randomly varying input values. This enables researchers to draw statistically valid conclusions about what sorts of outcomes are most probable.
  4. No one is likely to stop a simulation unless they realize they’ve made an error in setting it up—the sort of error that would invalidate the results or make the simulation run improperly.

The first two points should lead to feelings of both relief and disappointment. Why relief? Well to put it in a blunt and relatable way, the people running the simulation aren’t watching you when you masturbate (though a creepy neighbor or someone in your family might be, but they’re just another part of the simulation). Furthermore, they’re not keeping a record of your sins. (I suppose Hitler might register on their radar, though, when they’re performing their final analysis. CURSE YOU, GODWIN!)

The disappointing implication of these two points is that the vast majority of your life (perhaps all of it) will probably evaporate into oblivion as the simulation runs its course. In fact, the people running the simulation won’t just forget you, but they’ll probably never even know that you existed (except maybe as a relatively small set of data values buried within trillions of others). Your thoughts, memories, feelings, relationships, and legacies will not even be recorded at all.

If the above implications don’t make you feel utterly insignificant, perhaps the following will: A typical simulation is run tens of thousands of times in order to generate statistically significant data; so if we’re in a simulation, chances are that our universe is only one in a countless ensemble of runs. It could very well be that the only points of interest are the average values of some global characteristics of our universe (like the density of matter in space). Life itself could be a mere unintentional byproduct that goes entirely unnoticed by the makers. They might never know that humanity even existed.

This “ensemble of simulations” would constitute a multiverse in its own right—perhaps one that is equivalent to the “Many Worlds Interpretation” (MWI) of quantum mechanics. Each quantum process involves a roll of the dice (i.e., the use of a random number generator), and each iteration of the simulation would actualize a different set of outcomes. Assuming that a truly infinite number of simulations would be impossible, it might be too much to hope that all outcomes are realized. The overlords would just get a sampling of the possibilities.

This brings to mind one of my favorite quotes from Richard Dawkins:

We are going to die, and that makes us the lucky ones. Most people are never going to die because they are never going to be born. The potential people who could have been here in my place but who will in fact never see the light of day outnumber the sand grains of Arabia. Certainly those unborn ghosts include greater poets than Keats, scientists greater than Newton. We know this because the set of possible people allowed by our DNA so massively exceeds the set of actual people. In the teeth of these stupefying odds it is you and I, in our ordinariness, that are here. We privileged few, who won the lottery of birth against all odds, how dare we whine at our inevitable return to that prior state from which the vast majority have never stirred?

When I first read this, I thought, “Well, if the MWI of quantum mechanics is correct, then Dawkins is wrong. Every potential person does exist, somewhere. The unlucky ones aren’t those who are never born, but those who are brought into being to experience nothing but hardship and suffering.” But now I realize that there are possible MWI schemes in which not every possibility does come to fruition. A finite “ensemble of simulations” is one such scheme.

The third point—and this brings us back to the inciting thought—is that no one ever stops a simulation unless they’ve caught an error in the code and believe that the results won’t be valid. Especially for large and significant simulations, the programmers are likely to trouble-shoot the hell out of their code before running it. So it’s unlikely that anyone is going to shut down our simulation just because your life is boring. (And again, that thought was tongue-in-cheek anyway.) No, that’s not the reason you should lead an interesting life. There’s a much better one.

It may in fact be true that your life will amount to nothing from an outsider’s point of view. The simulator overlords (if they exist) will likely never know what you did with your limited time inside of their computer. No one will even have a record of it. But this, in a way, makes you more significant, not less—because you’re the only one who will know what you did with your life. So make it a good life, not for some outside observer who has the power to flip a switch, but for yourself—because your life belongs to you . . . and only you.